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Engineering Justification Paper
CPM7607 Marden MP (West Kent IPMP) Version: Final Date: December 2019 Classification: Highly Confidential
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1 Table of Contents
1 Table of Contents ................................................................................................................................... 2
2 Introduction ........................................................................................................................................... 3
2.1 General Background ..................................................................................................................................... 3 2.2 Site Specific Background ............................................................................................................................... 3
3 Equipment Summary .............................................................................................................................. 4
4 Problem Statement ................................................................................................................................ 5
4.1 Narrative Real‐Life Example of Problem ...................................................................................................... 5 4.2 Spend Boundaries ......................................................................................................................................... 7
5 Probability of Failure .............................................................................................................................. 7
5.1 Probability of Failure Data Assurance .......................................................................................................... 7
6 Consequence of Failure .......................................................................................................................... 7
7 Options Considered ................................................................................................................................ 8
7.1 Options ......................................................................................................................................................... 8 7.2 Option 1 Summary – Marden West .............................................................................................................. 9 7.3 Option 2 Summary – Marden East ............................................................................................................. 10 7.4 Option 3 Summary – Raise TRS Outlet Pressure ........................................................................................ 11 7.5 Option 4 Summary ‐ Interruption ............................................................................................................... 11 7.6 Options Technical Summary Table ............................................................................................................. 11 7.7 Options Cost Summary Table ..................................................................................................................... 12
8 Business Case Outline and Discussion ................................................................................................... 12
8.1 Key Business Case Drivers Description ....................................................................................................... 12 8.2 Business Case Summary ............................................................................................................................. 13
9 Preferred Option Scope and Project Plan .............................................................................................. 13
9.1 Preferred option ......................................................................................................................................... 13 9.2 Asset Health Spend Profile ......................................................................................................................... 13 9.3 Investment Risk Discussion ........................................................................................................................ 13
Appendix A ‐ Categorisation of Potential Load Growth ............................................................................ 15
Appendix B ‐ Development Trajectory Summary ..................................................................................... 16
Appendix C ‐ List of Acronyms ................................................................................................................. 17
SGN Cap Man – 011 CPM7607 Marden MP – EJP Dec19
3 December 2019
2 Introduction Reinforcement has been identified within the West Kent MP system, specifically relating to an anticipated system capacity failure at Marden. This project is part of a wider programme of reinforcement associated with the RIIO‐GD2 Business Plan Appendix covering Capacity Management (2019).
2.1 General Background The SGN distribution system is built to ensure security of supply for all our customers. Our networks operating at pressures below 7bar are designed to meet a peak six‐minute demand level that could be experienced under 1:20 conditions, supporting a safe, secure and reliable service to those customers and meeting requirements outlined within our Licence Condition, including, but not limited to, Condition 16 contained therein.
Link: Gas Transporters Licence – Standard Conditions
Where capacity constraints are identified that are likely to impact on SGNs ability to ensure security of supply to all customers, Network Planning will look to establish optimum, cost‐efficient reinforcement strategies to mitigate that risk. Such constraints may arise as a result of a number of factors, but the most common is increased demand levels, often resulting from new connections.
SGN has initiated an extensive programme of stakeholder engagement, working closely with Local Authorities, both in Scotland and the South of England, to establish a fully informed and independently sourced picture of planned development.
This engagement has provided SGN with confidence that the sites identified will progress to development and, to support this level of growth, SGN has developed a programme of reinforcement across its network.
2.2 Site Specific Background Development within the West Kent Grid is covered by the following District Councils local plans; Tonbridge & Malling Council, Tunbridge Wells Council, Maidstone Council, Rother Council, Ashford Council and Wealden Council local plans. The local plan presents a vision and spatial strategy for directing growth in the district for the future and sets out where development is expected to take place.
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Figure 1: Council and West Kent District Boundaries
Three domestic and two non‐domestic developments located in the surrounding village of Marden trigger reinforcement. Marden itself is part of Maidstone and is found south of the town. Through engagement with Maidstone Borough Council, they provided the following information regarding the ‘trigger’ sites:
H1 (43) Howland Road, Marden – A reserved matters application has been approved and a site survey in March 2018 monitored it as under construction
H1 (46) Marden Cricket and Hockey Club, Stanley Road, Marden – Revised full planning application submitted. Developer stated in May they are committed to building out the site, possibly commencing in 18 months from November 2019
H1 (47) South of the Parsonage, Goudhurst Road, Marden – Full plans planning permission granted in July 2018. The developer stated strong commitment to build out the site in May 2018, possible commencement in 18 months from November 2019
EMP1 (2) South of Claygate, Pattenden Lane, Marden ‐ No current planning application
EMP1 (3) West of Wheelbarrow Industrial Estate, Pattenden Lane, Marden ‐ Development of 4,307sqm B2 floorspace completed under 14/4058 (previous year) in the northern portion of the site. The remaining area of 1.9ha has no planning application at present.
See Appendix B for a full development trajectory of all sites.
3 Equipment Summary On the West Kent MP network, Marden is found at the equalising point of two gas flows; one supplied from the west by East Peckham DPG (1.9bar), the other supplied from the east by Rolvenden TRS (1.9bar) and 4 Throws Hawkhurst TRS (1.9bar). Marden is fed from the east and west through two long lengths of 125mmPE MP.
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4 Problem Statement Why are we doing this work and what happens if we do nothing? New connections to our networks reduce available capacity and when pressures are predicted to fall below minimum acceptable levels it is necessary to reinforce or increase pressures to facilitate increased capacity in the system.
In the case of Marden MP system, the potential development identified within the Local Plan and associated documents for Maidstone, will see the system approach capacity within RIIO‐GD2.
Failure to reinforce the network will restrict the delivery of these developments.
What is the outcome that we want to achieve? Maintain SGN’s Licence Conditions to ensure security of supply and support economic prosperity by not becoming a blocker to development.
How will we understand if the spend has been successful? On completion of the proposed reinforcement, SGN will monitor system performance to ensure expected system pressures are maintained. This will take the form of regular system performance checks and localised pressure surveys to ensure a successful outcome has been achieved.
At a customer level, SGN will have delivered a reinforcement that ensures a safe and secure network, meets stakeholder aspirations and ensures developments progress timeously.
4.1 Narrative Real‐Life Example of Problem The area surrounding the town of Marden has been identified for major development, with a significant impact on capacity available within the MP system. The existing network will require significant reinforcement to support these sites. A recent example of good planning to meet customer expectation, whilst also ensuring security of supply, occurred following the acceptance of a quotation to supply a new development at Milton Heights, Milton, Abingdon, Oxfordshire (P18143337).
Security
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Network analysis confirmed a requirement to reinforce SGN’s system in advance of connecting the fully developed site load. However, network analysis also confirmed an interim load/connection of 72 new properties in advance of reinforcement, thereby meeting the GT/Developer’s schedule of works.
Reinforcement to supply the full development was subsequently planned and completed in advance of connections beyond the interim load, ensuring security of supply to approximately 500 new/existing customers.
Table 1 – Development Summary
Development Name Site Usage Site Status Confidence
Howland Road 44 Houses Under Construction Highly probable (>90% confidence)
Marden Cricket and Hockey Club
124 Houses Revised full planning application submitted
Highly probable (>90% confidence)
South of the Parsonage, Goudhurst Road
65 Houses Full Planning Consent Highly probable (>90% confidence)
Proposed Marden Development
2,000 Houses Identified potential site Poor prospects (<50% confidence)
South of Claygate Employment No Planning consent Good prospects (>50% confidence)
West of Wheelbarrow Industrial Estate
Employment No Planning consent Good prospects (>50% confidence)
Please see Appendix A of this document which gives further details of the criteria applied when determining the attributable ‘confidence’ level of the above sites progressing to development.
Through this determination SGN has deemed the requirement for this reinforcement within the RIIO‐GD2 period as ‘Medium’ and has therefore included the funding request in both our Base Growth and High Growth scenarios.
Security
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4.2 Spend Boundaries The spend associated with these reinforcement works will provide capacity within the West Kent MP system to support projected development during RIIO‐GD2.
The monies associated with these works ensure security of supply for existing customers and connection of planned development to the network.
Costs contained within this paper have been prepared using average contracted rates at depot level and validated against known costs for similar, completed projects.
Not included within this spend are the costs for subsequent phases of reinforcement required to support demand out‐with the RIIO‐GD2 period and/or any costs associated with reinforcement of the upstream transmission system.
5 Probability of Failure As development identified for Marden progresses, the MP Network is predicted to fail at >90% peak demand by winter 2025/26, putting at risk supplies to approx. 1,400 new and existing customers.
5.1 Probability of Failure Data Assurance
Model Validation To ensure the accuracy of the Network Analysis models, validation is carried out in line with the published requirement under Section 17 of SGN’s Safety Case and is a fundament of SGN’s Licence to Operate.
Validation ensures that the current models are an accurate representation of the actual gas transportation system and can be used to predict network behaviour under a variety of conditions, including the 1 in 20 design condition.
In addition to the Validation Programme, a robust model maintenance process and annual winter system performance checks ensure that the models continue to be accurate and fit for purpose.
Network Growth The Maidstone Local Plan and associated documents have been reviewed and an assessment made as to the probability of sites contained therein progressing to construction (see Table 1). The resulting outputs have been applied to the network model, providing confidence that pre‐emptive repair of the network (i.e. reinforcement) will be required during RIIO‐GD2 to ensure SGN meets its Licence Conditions, maintaining minimum supply pressures under all demand conditions.
6 Consequence of Failure Loss of Supply to Customers Failure to reinforce will put at risk the supply to customers supplied by the West Kent MP network. Ultimately this will result in the failure of a number of DGs in Marden and potentially the loss of supply to approximately 1,400 new and existing customers, attracting adverse publicity and damage to the company’s reputation.
Other than domestic customers, affected customers will include Marden Primary School, Marden Sports Club, a medical centre and multiple small commercial businesses.
Financially, after the first 24 hours, affected householders will be compensated for time without gas. Domestic customers will receive £41 for each 24‐hour period without gas, small businesses will receive £69 for each 24‐hour period without gas.
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Table 2 ‐ Projected RIIO‐GD2 (2025/26) Pressures without Reinforcement
Location Min Required Pressure (bar) Min. Modelled Pressure (bar)
Marden 0.35 0
Safety Impact of Failure
Reinforcement of the West Kent IPMP system is necessary to meet the requirements of our Licence Condition.
In this instance, a failure to reinforce will result in a system failure during peak winter conditions. The resulting loss of supply may have serious health and safety implications for vulnerable customers who rely on gas for essential heating and cooking facilities.
Environmental Impact
A system failure on this scale will result in a major recovery exercise. Environmental impacts will include increased travel to site by SGN operatives, leading to an increase in greenhouse gas emissions and disruption to the public.
On site, the use of fossil fuels to power plant and equipment required in the restoration of supplies will further increase greenhouse gas emissions, as will subsequent travel/plant in use for the reinstatement of public highways following the conclusion of these works.
7 Options Considered
7.1 Options In accordance with the guidelines set out in the Ofgem guidance document ‘Engineering Justification Paper Frameworks for RIIO‐GD2 and RIIO‐GT2’ – Appendix B (Section 7), the following options have been considered:
Replace on Failure
Security
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Wait until the network fails then replace the system. This option has been discounted due to non‐compliance with SGN’s Licence Condition.
Repair on Failure Mains reinforcement after the network has failed. This option has been discounted due to non‐compliance with SGN’s Licence Condition.
Pre‐Emptively Replace Replace the system prior to network failure. This option has been discounted as it is impracticable to replace the MP system.
Pre‐Emptively Repair Mains reinforcement and/or Interruption based on model data prior to network failure. Four options have been considered for further investigation:
Option 1 ‐ Marden West
Option 2 – Marden East
Option 3 – Uprating of MP System
Option 4 – Interruption
Do Nothing This is not considered an option. The combination of committed development and identified growth dictates the requirement to provide additional capacity on this system through reinforcement.
7.2 Option 1 Summary – Marden West The technical detail of option This option involves the construction of approximately 2km x 180mmPE MP. It reinforces the existing parallel 125mmPE MP main.
The basis for cost estimate/unit cost Costs for this option, amounting to £1.005M, have been prepared using average contracted rates at depot level and validated against known costs for similar, completed projects.
The perceived benefits of the option This option delivers a robust reinforcement solution and strengthens a weak area within the West Kent MP network. It may also be possible to phase the reinforcement in line with development and spread the costs over a number of years instead of just one, which is the current plan.
Delivery Timescales The reinforcement is scheduled for 2022/23 and it is expected to be completed in the same financial year.
Key Assumptions Made It has been assumed that during RIIO‐GD2 the 2,000‐home development on the outskirts of Marden will not be constructed in the GD2 time frame. At present the development is speculative, it has been included in the Maidstone Council’s Call for Sites, put forward by one developer, but has no other evidence that it will go ahead, therefore has not been included in the analysis for this project.
It is assumed that known potential demand growth both within RIIO‐GD2 period and beyond will require the same level of gas supply as that currently experienced.
Any other items that differentiate the option from the others considered Compared to the Option 2 this one has the best return in pressure at Marden.
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7.3 Option 2 Summary – Marden East The technical detail of option This option involves the construction of approximately 2km x 180mmPE MP. The option is the same length and diameter as the first option, but instead of being located to the west of Marden is found reinforcing the existing 125mmPE parallel main to the east of Marden.
The basis for cost estimate/unit cost Costs for this option, amounting to £1.005M, have been prepared using average contracted rates at depot level and validated against known costs for similar, completed projects.
The perceived benefits of the option This option delivers a robust reinforcement solution and strengthens a weak area within the West Kent MP network. It may also be possible to phase the reinforcement in line with development and spread the costs over a number of years instead of just one, which is the current plan.
Delivery Timescales The reinforcement is scheduled for 2022/23 and it is expected to be completed in the same financial year.
Key Assumptions Made It has been assumed that during RIIO‐GD2 the 2,000‐home development on the outskirts of Marden will not be constructed in the GD2 time frame. At present the development is speculative, it has been included in the Maidstone Council’s Call for Sites, put forward by one developer, but has no other evidence that it will go ahead, therefore has not been included in the analysis for this project.
It is assumed that known potential demand growth both within RIIO‐GD2 period and beyond will require the same level of gas supply as that currently experienced.
Security
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7.4 Option 3 Summary – Raise TRS Outlet Pressure This option was disregarded, as the increase to the three TRS’ outlet operating pressure supplying Marden did not provide the required minimum system pressure across the MP network.
7.5 Option 4 Summary ‐ Interruption In addition to the above, consideration was given to Interruption.
As part of Interruption Reform, also known as the Mod 90 process, SGN has the option to offer a tender for interruptible contracts to customers to offset the need to invest for capacity.
Interruptible consumers receive discounted transportation charges for the flexibility they provide to the system for demand side management at times of high demand.
All eligible interruptible sites were reviewed, none are in a location where they could be considered as an alternative to reinforcement.
7.6 Options Technical Summary Table Table 3 ‐ Options Technical Summary Table
Option First Year of Spend
Final Year of Spend
Volume of Interventions
Design Life (Years)
Total Cost (£M)
1. Marden West 2022/23 2022/23 2km x 180mmPE MP 10 1.005
2. Marden East 2022/23 2022/23 2km x 180mmPE MP 10 1.005
3. Raise TRS Outlet Pressure
n/a n/a n/a n/a n/a
4. Interruption n/a n/a n/a n/a n/a
Costs inclusive of Overheads and Efficiencies
Security
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7.7 Options Cost Summary Table Table 4 ‐ Options Cost Summary Table
Option Volume of Interventions Cost Breakdown
(£M) Total Cost (£M)
1. Marden West 2km x 180mmPE MP 1.005 1.005
2. Marden East 2km x 180mmPE MP 1.005 1.005
Costs inclusive of Overheads and Efficiencies
8 Business Case Outline and Discussion A full review of the relevant Local Plans and associated documents, followed by close engagement with stakeholders, has provided confidence in the level of development expected during RIIO‐GD2.
The development outputs have been applied to the network model, which predicts a failure at >90% peak demand by winter 2025/26, putting at risk supplies to 1,400 new and existing customers.
To mitigate this risk and meet Licence Conditions it will be necessary to pre‐emptively reinforce the network during the RIIO‐GD2 period.
There have been no external costs incurred in assessing the options considered as these have been prepared by the in‐house Network Planning and Design teams.
8.1 Key Business Case Drivers Description
Pre‐Emptively Repair: Option 1 – Marden West Marden is supplied from the east and west by 125mmPE MP, as the village continues to grow, pressure loss increases over the 125mmPE mains. Therefore, reinforcement from either end would benefit this growing area. Option 1 reinforces the 125mmPE MP from the west and is the primary option as it provides a greater increase in pressure to the Marden area when compared to Option 2.
The existing mains follow the narrow main road in and out of Marden. The road connects all nearby villages and the reinforcement would likely cause disruption to traffic.
Reinforcement can potentially be phased in line with the developments that drive the reinforcement, providing some flexibility in the scheduling and splitting costs over multiple years instead of just one. At present however, the option is initially planned to be constructed in 1 year.
Pre‐Emptively Repair: Option 2 – Marden East Option 2 reinforces the existing 125mmPE MP from the east. The reinforcement is less efficient than Option 1 and lies on the road directly outside the village of Staplehurst where some houses are situated. This option is likely to be more disruptive to traffic than Option 1. Business Case Summary
Reinforcement can potentially be phased in line with the developments that drive the reinforcement, providing some flexibility in the scheduling and splitting costs over multiple years instead of just one. At present however, the option is initially planned to be constructed in 1 year.
Table 5 ‐ Summary of Key Value Drivers
Option No. Name of Option Key Value Driver
1 Marden West Best return in pressures at Marden. Medium‐term solution.
2 Marden East Medium‐term solution.
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8.2 Business Case Summary This project is driven by SGN’s Licence Conditions to ensure security of supply.
Table 6 ‐ Business Case Matrix
Marden West Marden East
CAPEX (£M) 1.005 1.005
Design Life 10 years 10 years
Positive Impact (Pros)
Meets license obligations to maintain security of supply. May be possible to phase reinforcement over a number of years, splitting costs. Better pressure
returns at Marden compared to Option 2.
Meets license obligations to maintain security of supply. May be possible to phase reinforcement over a number of
years, splitting costs.
Negative Impact (Cons)
Likely to cause disruption to public and land owners.
Likely to cause disruption to public and land owners. Lesser pressure returns at
Marden compared to Option 1.
Costs inclusive of Overheads and Efficiencies
9 Preferred Option Scope and Project Plan
9.1 Preferred option
Pre‐Emptively Repair: Option 1 – Marden West Approx. 2km x 180mmPE MP.
9.2 Asset Health Spend Profile
Table 7 ‐ Summary of Schedule of Spend
Asset Health Spend Profile (£M)
Pre GD2 2021/22 2022/23 2023/24 2024/25 2025/26 Post GD2
0 0 1.005 0 0 0 0
Costs inclusive of Overheads and Efficiencies
9.3 Investment Risk Discussion
Delay/Cancellations The project is demand driven by a small number of developments. If these developments are delayed or the developer pulls out, then the investment will be a risk, as the reinforcement may be postponed to a later date or no longer be required.
Maidstone Council was contacted regarding the details of the developments. For all housing, which is the main trigger for the reinforcement, the council gave SGN confidence that the developments would go ahead and in the next few years.
Costs SGN have prepared costs using average contracted rates at depot level and have validated them against known costs for similar, completed projects. Nevertheless, whilst all reasonable steps have been taken to ensure accuracy of costs outlined in this paper, it is recognised that external variables may change and subsequently impact on actual costs at time of construction. Examples of such could include unforeseen increases in contractor rates driven by a surplus of market demand for labour or sharp cost increases for materials.
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Costs Under/Overspend Factors such as market driven demand linked to the economy, the UK’s potential exit from the European Union, emerging decarbonisation strategies and industry innovation can potentially impact on the scope of works outlined in this paper. SGN has proposed a volume driver funding mechanism to de‐risk underspend/overspend for these works. Further details of this proposal can be found in Section 6.2 in the RIIO GD2 Business Plan Appendix for Capacity Management.
Political/Environment Situation (i.e. low/zero carbon) As stated in the SGN Environmental Action Plan, and in line with current UK Government targets, SGN’s long term target is to achieve Net Zero emissions by 2045. This means a decarbonisation of the energy network and supporting the transition to an environmentally sustainable low‐carbon energy system. Indeed, SGN recognise that there have been preliminary government targets set facilitating a move toward a renewable or low carbon heat solutions by the end of the RIIO‐GD2 period. As such, throughout the RIIO‐GD2 period we will continue to closely monitor this emerging heat strategy with a view to refining any potential impact on current growth forecasts.
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Appendix A ‐ Categorisation of Potential Load Growth The following Table sets out the manner in which identified potential load growth has been categorised and applied, leading to customer driven reinforcement, when looking to establish the optimum investment strategy for SGN’s networks.
DEFINITION TABLE
Confidence Definition Factors to be considered Base
Growth High
Growth
Highly probable (>90%
confidence)
Connection expected in RIIO‐
GD2 for all sites
1. Quotation accepted but not yet on stream 2. Building is in progress. 3. Detailed planning permission granted. 4. Economic conditions indicate that sites for
consumers of a particular type are likely to be developed, e.g.
a. Domestic sites where there is a high demand for housing and there is a shortage of land available.
b. Interest has been shown in having a connection made to a non‐domestic site and economic factors suggest development will go ahead.
Probable (>75%
confidence
Connection Likely in RIIO‐GD2
for majority of
sites
1. Outline planning consent has been granted. 2. Recent development has been carried out in
the area. 3. The land is a prime site for development, but
no connection enquires have yet been received.
4. Adopted Local Plan Site
Good prospects (>50%
confidence)
Connection expected for some sites in RIIO‐GD2
1. Proposed Local Plan Site 2. No indication of planning permission being
granted for the site. 3. The site is outside existing gas supply areas. 4. The site would involve physical problems in
delivering a gas supply. 5. The site would require substantial additional
infrastructure, e.g. additional roads, schools. 6. Site marked “reserve” in Local Plan. 7. Site is known to be contaminated ground. 8. Site has “protection” orders served over it –
e.g. SSSI.
Poor prospects (<50%
confidence)
Significant time or
investment required to progress
1. Does not meet the above planning criteria. 2. Site has been deemed as ‘speculative’. 3. The site would require significant additional
infrastructure, e.g. additional roads, schools.
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Appendix B ‐ Development Trajectory Summary
Table 8 ‐ Domestic Development Trajectory (Dwellings)
Town Site Sum of GD1
Sum of GD2
Sum of Post GD2
Sum of Total
Marden Howland Road 44 0 0 44
Marden Marden Cricket and Hockey Club, Stanley
Rd 0 64 0 64
Marden S of Parsonage, Goudhurst Rd
0 124 0 124
Marden Proposed 2,000
Home Development n/a n/a n/a n/a
Grand Total 44 188 0 232
Table 9 ‐ Non‐Domestic Development Trajectory (scmh)
Town Site Sum of GD1
Sum of GD2
Sum of Post GD2
Sum of Total
Marden South of Claygate, Pattenden Lane
0 36 0 36
Marden West of Wheelbarrow Ind Est, Pattenden Lane
0 66 0 66
Grand Total 0 102 0 102
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Appendix C ‐ List of Acronyms
Acronym Backronym
(spelled out acronym) Definition / explanation
Pressure Tiers
o HP o IP o MP o LP
o High Pressure o Intermediate Pressure o Medium Pressure o Low Pressure
o High Pressure i.e. above 7bar LTS (NTS) o Intermediate Pressure i.e. 2 – 7bar o Medium Pressure i.e. up to 2bar o Low Pressure i.e. up to 75mb
CSEP Connected System Exit Point Third party connection to Gas network from an iGT or UIP
DG District Governor Pressure regulator primarily used for reducing pressures from IP and MP tiers to LP.
DPG Distribution Pressure Governor
Pressure regulator primarily used for reducing pressures from IP tier to MP.
HDPE High Density Polyethylene Material standard for plastic pipe – High density allows for use at > 2bar operation due to thicker pipe wall. Reduced internal diameter increases weight of pipe, is not suitable for use < 2bar. Cheaper material and jointing than Steel.
iGT (GT) Independent Gas Transporter Third party supplier of gas and infrastructure to closed developments, not generally adopted by SGN.
LTS Local Transmission System High Pressure system feeding from National Offtakes to P(T)RS Inlets
MDPE Medium Density Polyethylene Material standard for plastic pipe – Medium density allows for greater internal diameter for extra capacity required at lower tiers, but thinner pipe wall thickness is not considered safe for operation at >2bar. Cheap material and jointing due to electro fusion welding.
MOP Maximum Operation Pressure Highest design pressure for a mains system, however regulator may be set lower than this but not higher.
NTS National Transmission System High Pressure system feeding National Offtakes from Terminals
PMAC Pressure Management and Control
Third Party monitoring system which communicates live data via BT Comms link, facilitates remote control of pressure settings and profiles on SGN Plant, used at all Plant levels.
P(T)RS Pressure (Transmission) Regulator Station
Pressure regulator primarily used for reducing pressures from HP (LTS/NTS) tier to IP / MP or LP.
UIP Universal Infrastructure Provider
Provides and connects infrastructure to gas network but does not supply gas. UIP infrastructure is generally adopted by SGN.
RIIO‐GD1 Revenue=Incentives + Innovation + Outputs – Gas Distribution 1
8‐Year price control period (2013‐2021)
RIIO‐GD2 Revenue=Incentives + Innovation + Outputs – Gas Distribution 2
Proposed 5‐Year price control period (2021‐2026)
SHP SHP File Format SHP is a file extension for a Shapefile shape format used in geographical information systems (GIS) software.
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ST STEEL Steel pipe material is used where PE cannot i.e. protection from heavy traffic or bridge crossings, Regulator outlets where excessive gas cooling may be experienced at pressure reduction. Steel pipe laying can be expensive due to welded joints.
1:20 1:20 Demand Conditions Designing a network to operate whilst experiencing demand conditions historically only seen every 20 years, during severe weather events.